challenger starting

[napaguy]

problem with 72 challenger with electronic ign. turns over great, no spark. checked ballast, ecu ,new distr, has new engine wiring harness. with key on only have 10 volts at ballast and number 2 pin on ecu, battery has 13. when cranking, voltage at ballast and ecu drops to zero. I am thinking something wrong with inside wiring maybe the key. any ideas on where to check next

 

[Adam]

Since you have voltage in the run position but not while cranking I would verify the starter relay wiring. You should obviously have voltage to the ECU while cranking. I would back track the hot wire feeding the Starter relay, ECU, ballast, ign switch, bulkhead connectors column harness connector, etc.

 

[AUSTA]

You may be missing the brown when the key is on the blue should be hot through the resistor to the coil which you have
When you turn to start the brown from the key should supply full power to the coil for start .
Once you have that follow the steps above.

 

[napaguy]

I see what you are saying, but why do I only have 10 volts at ecu and ballast and then none? I am showing only 10 at fuse panel too. could amp gauge be some of problem? I haven't checked any further. I have 12 volts at red wire at firewall plug. where could it be losing voltage from there. thinking about pulling cluster and eliminate amp gauge. anybody did this?

 

[AUSTA]

Eliminating high current internal cabin wiring is always a good thing the ammeter & undersized wiring was known to cause fires.
Where are you testing the positive 12 volts to the battery negative terminal or the body frame could be a bad ground .
Also check the steering column wiring plugs.
Would rewire the Ammeter charge wiring first to eliminate voltage drop.

 

[napaguy]

thanks for the replies. gonna do more testing after holidays